Pen cap



FIG. 1 is a perspective view of a pen cap showing my new design;

FIG. 2 is a front view;

FIG. 3 is a rear view;

FIG. 4 is a left side view, the right side being a mirror image thereof;

FIG. 5 is a top view;

FIG. 6 is a bottom view; and,

FIG. 7 is a sectional view taken 7—7 line in FIG. 2. 

The ornamental design for a pen cap, as shown and described. 